Chemical and water box for paper making machinery



Nov. 30, 1965 A. E KEYWORTH ETAL CHEMICAL AND WATER BOX FOR PAPER MAKING MACHINERY Filed Sept. 28, 1962 2 Sheets-Sheet l Nov. 30, 1965 A. E. KEYWORTH ETAL 3,220,339

CHEMICAL AND WATER BOX FOR PAPER MAKING MACHINERY Filed Sept. 28, 1962 2 Sheets-Sheet 2 United States Patent 3,220,339 CHEMICAL AND WATER BOX FOR PAPER MAKING MACHINERY Arthur E. Keyworth and William Kleimola, East Walpole,

Mass, assignors to Bird Machine Company, South Walpole, Mass., a corporation of Massachusetts Filed Sept. 28, 1962, Ser. No. 227,027 9 Claims. (Cl. 100-74) This invention relates to improved equipment for spreading liquids across a wide span of a moving surface, such equipment in the paper making industry usually comprising an elongated receptacle called a Water box. Such boxes spread liquids against the surface of rotating rolls or paper webs on such rolls in paper making machinery, and when used in conjunction with a doctor blade are sometimes called water doctors. Water boxes or water doctors are used for applying to calender rolls, and thence to a moving paper sheet or other web, coatings or chemical treating solutions, surface sizing, colors, dyes or other liquids.

An ideal water box should be low in cost, easy to make and use, and adapted for handling many different liquids, heated or not, with or without solids suspended therein. In use, such a box should accomplish constant spreading or flow of a consistently composed sheet of liquid at a controlled rate and depth uniformly across the entire width of the machine so that variations in the amount and character of liquid applied will be eliminated both longitudinally and transversely of the moving paper web or roll surface being wet or treated with the liquid. In prior designs specific problems are found in, (a) controlling, distributing and mixing the liquid coming into the box so that the flow rate, temperature and/ or composition of the incoming liquid is the same at all points, (b) maintaining a desired level of liquid in the box for uniform rate of spreading or flow therefrom, (0) emptymg or dumping of liquid from the box quickly in an emergency, (d) controlling and adjusting the liquidspreading lip or other means for obtaining a desired uniform flow of liquid from the box across the entire machine width, and (e) properly sealing liquid between the ends of the water box and spreading lip so that the side edges of the surface being wet may be adjustably defined and precisely maintained.

The objects of this invention are to essay an ideal water box and provide a combination of constructions and features which together alleviate or eliminate the problems enumerated above and auxiliary problems in manufacture and of use of such equipment. This is done while utilizing a maximum of standard, readily available structural shapes, materials and components for the major elements of the water box, keeping specially formed castings or other fabricated parts to a minimum, simplifying the water box itself, its adjustable end seals, mounting of the spreading lip and seals for the liquid in the box, the liquid feed to the box and the arrangement for maintaining proper liquid level in the box, this last improvement being also adapted to provide a quick dump or unloading of the liquid in emergencies. In particular, and referring to comparably lettered portions in the preceding paragraph, the invention provides, (a) a single liquid inlet header extending lengthwise of the box, carrying a multiplicity of individually controllable branches with ends discharging at regularly spaced intervals along the box in such position and direction as to agitate the liquid in the box, (b) a rotatable pipe elbow in the box, the angular position of which determines the level of liquid remaining in the box, (c) this same pipe elbow being rotatable to a position for emptying or dumping the liquid quickly, (d) a clamping dam or wall adjustably and removably holding the apron cloth or other liquidspreading element in the box by pressure, the dam forming a liquid seal along the length of the box, and (e) this clamping dam removably supporting box end sealing members at selected adjustable positions near the ends of the box pressed against the liquid-spreading element when the dam exerts sealing pressure. A particular form of adjustable end seal for a water box is also regarded as a part of this invention.

Other objects, advantages and further details of that which is believed to be novel and included in this invention will be clear from the following description and claims, taken with the accompanying drawings in which is illustrated an example of chemical and water box embodying the present invention and incorporating improvements outlined above.

In the drawings:

FIG. 1 is a top plan view on a reduced scale showing a chemical and water box according to the invention;

FIG. 2 is a rear elevational view of the box of FIG. 1;

FIG. 3 is an enlarged vertical section through the box on line 33 of FIG. 1 showing general construction;

FIG. 4 is a similar vertical section on line 44 of FIG. 1 showing a sealing arrangement for the end of the box;

FIG. 5 is a horizontal section on line 55 of FIG. 4;

FIG. 6 is a vertical section on line 6-6 of FIG. 4;

FIG. 7 is an enlarged vertical section through the box on line 7-7 of FIG. 1, showing an overflow or liquid outlet arrangement;

FIG. 8 is a vertical section on line 88 of FIG. 7;

FIG. 9 is an enlarged vertical section on line 9-9 of FIG. 1 showing details of a liquid inlet to the box, and

FIG. 10 is an end or side elevational view of the Water box of FIG. 1 showing its mounting with relation to parts of a papermaking machine.

In carrying out the objects of this invention, in one embodiment thereof a water box 15 is provided in the form of an elongated piece of aluminum of a standard L-shaped cross-section. This piece has a back wall 16 and a bottom wall 18 at right angles to each other to receive and contain the water or other liquid and act as the sole structural supporting member for the various elements and mechanisms hereafter indicated. The box extends across the full width of a papermaking machine and is therefore unsupported itself throughout a span of about ten feet or more.

The angle piece forming the box is supported for tional adjustable tilting mechanisms 23 of a character readily understood, the box may be pivoted and the free edge of the bottom wall 18 may be moved in an arc toward or away from the surface of a rotary roll or drum 26 turning in the direction indicated by the arrow in FIGS. 3 and 4. Substantially the entire bot-tom wall 18 of the tiltable box serves as a support for the primary liquid spreading element, an apron cloth 28 of known elongated rectangular strip design and character, the front edge or tip of this apron cloth extending beyond the free edge of the bottom wall 18 and providing a liquidspreading lip lying against the surface of the roll 26 as shown. It is preferred that the apron cloth does not lie directly upon the surface of the bottom wall 18 but is separated therefrom by a seal mat 30 made of a resilient water repellent sheet of rubber or rubber-like material. This seal mat or strip, like the apron cltoh 28, has one long edge extending beyond the free edge of the bottom wall 18 so that it supports all excepting the extreme tip or lip of the apron cloth where it extends beyond the edge of the water box.

The apron cloth is made readily adjustable and easily replaceable by being held in place in the water box and against the seal mat 30 by a clamp or dam- 32 made of stainless steel or similar suitable material not subject to attack by the chemicals or water to be contained in the water box. This dam 32 is an elongated flat plate or wall suitably mounted to slide in a plane parallel to the back wall 16 and normal to the bottom wall 18, being carried in dam supporting brackets 34 which are bolted or other wise secured to the inside of back wall 16. Each of these brackets, of which there are several across the width of the machine on the water box, threadedly receives a clamping bolt 36 which applies sealing pressure to the dam against the apron cloth and between the apron cloth, the seal mat and the bottom wall of the box. After the lip of the apron cloth has been properly adjusted to lie against the drum 26 in proper position, the bolts 36 are tightened and move the darn 32 until its lower edge clamps and seals the apron cloth firmly in its adjusted position so that chemicals, water of other liquid L may be contained in the triangular space in the box between the dam 32 and the upper face of the apron cloth at a level established by the degree of tilting of the water box proper and limited further by an outlet or overflow arrangement hereinafter described. In operation of the machine, the liquid in the box flows over the extended lip of the apron cloth and is spread against the surface of the rotating roll 26 or a web of paper being carried by the moving roll.

When the apron cloth becomes worn beyond a point where it may be readjusted in the Water box, or when it is otherwise desirable to change or replace the apron cloth, the same may be quickly removed after loosening the clamping bolts 36, the pres-sure on the clamp or dam 32 then being relieved sufficiently so that the aproncloth, the seal mat, or both, may be slipped out endwise of the water box or forwardly toward the roll, if the box is raised. Because both the cloth 28 and the mat 30 are simple elongated strips of flat material with no projections or formations thereon for holding them in place, there will be no complications in their removal when once the clamping dam 32 has been loosened.

The clamping and sealing arrangement for the main portion of the apron cloth as above described lends itself to an improved-adjustable end or edge seal assembly 38 which constitutes an effective end wall for containing the liquid in the water box. Obviously, an end seal assembly 38 is provided near each end of the water box, being held in place by an end seal clamp 40 adjustably secured at any selected longitudinal position along the top edge of the dam 32 as by the adjusting bolts 42, threaded into the clamp 40 with their tips bearing against the front face of the dam where it is slidably contained within a slot 43. The rest of the end seal assembly is firmly held, clamped and sealed in adjusted position as by a clamping bolt 44 threaded through an extension on the clamp 46 as shown, anddirected at an angle toward the junction of the dam and the apron cloth. The actual sealing portion of the end seal assembly is contained between a pair of end seal side plates 46, these side plates supporting a resilient box-like end sealing member of rubber or rubber-like material having an end seal bottom wall 46, opposite side wall-s 49 and a back wall 50. In the center of the assembly there is a filler 52 of wood or other material which spaces the side walls 49 of the seal'and the side plates 46 and serves as a backing for the bottom wall 48 and back wall 50 of the seal, leaving a cavity or open spacebetween the side plates 46 infront of the filler, over the portions of the seal mat and the apron cloth Where they extend beyond the free edge of the wall 18. The end of the clamping bolt 44 bears against the top of filler 52 to hold the end seal assembly in place. The end seal assembly is held together as by bolts 54 and cooperatingnuts 55 so that ifany part of the seal assembly becomes unfit for use it is an easy matter to remove the undesirable part and substitute a suitable one with little delay. The assemblies are symmetrical and identical so that they may be used on either end of the water box.

The cavity above described, in front of the filler 52 and between the side plates 46, provides a container for a simple but effective end spill seal which can be used to prevent oozing of excess liquid from the ends of the water box near the tip of the apron cloth. This spill seal takes the form of a liquid-repellent resilient packing 56 composed of a somewhat loosely compacted mass of cotton scraps or waste bound together with a waterproof grease, and when liquid starts to leak from the end of the water box an operator need merely tap the top of the packing with a finger tip until the leakage stops, this being usually sufficient for the purpose. In cases of more persistent leakage a small weight or spring pressure might be provided above the packing 56 to hold it more firmly in place against the apron cloth, but normally the resiliency and expandability of the packing within the cavity will exert sufiicient sealing pressure to control leakage from the ends of the sealing mat and apron cloth where they extend beyond the bottom wall of the box.

Obviously, because the end seals are both carried by the dam 32, being clamped thereto in one or another of their longitudinally adjusted positions along the dam, when the apron cloth and dam clamping bolts 36 are released, pressure of the end seals on the apron cloth and seal mat will be similarly released and the cloth and mat may be removed by sliding as above explained.

As above described, the angle of tilt of the water box about its trunnions 20 will establish a primary level or ,head of liquid in the water box in front of the dam 32 and above the top surface and extended tip or lip of the apron cloth 28. However, this liquid level is not always exactly suited for the desired rate of spreading or coating of. liquid from the apron cloth tip to the rotating drum or paper web. Therefore, and according tothis invention, a simplified outlet or overflow level control is provided near one or both ends of the water box within the space between adjusted end seal positions. This overflow level control consists of an open pipe elbow 58,- one leg of which has its end opening into the water box as at 60, the other leg of this elbow extending as at 62 rotatably through an opening in the dam 32 and extending to a discharge conduit or other drainage connection 64. Ohviously, the back wall 16 of the water box must have a suitable clearance opening 66 therein through which the leg 62 of the level control elbow will pass freely, but this leg of the elbow is sealed where it passes rotatably through the dam as by a resilient .O-ring seal 68 surrounding leg 62 and engaged against an annular shoulder 69 on the elbow as well as against the front face of the dam 32. A collar 70, welded to the darn, provides a rotary bearing for the leg 62 and a holding collar 72, provided with a set screw 73, holds the elbow against sliding while permitting rotation in the sealing and clamping dam.

As should be clear from the drawing, the angular position of the open end- 60 of the overflow elbow will determine the level at which liquid will start to spill or overflow from the water box and be drained away from it through the discharge conduit 64. Controlling this angular position, a split clamp ring 74 is clamped as by a bolt 76 around the drain leg 62 of the elbow where it extends outside of the back wall 16 of the water box. On a side extension of this split ring 74 a hole is provided for the reception of a pivot pin 78 which extends from one end of an offset connecting link 80, in turn carried by one end of a sliding level control link 82. Control link supporting and guiding brackets 84-secured to the outside of the wall 16 serve their purpose of carrying and directing the control link in proper sliding movement toward and away from the rotary control elbow to determine its angular position. The sliding position of the control link 82 maybe fixed by hand if desired, or may be automatically controlled as through an hydraulic link control piston 86 as shown in the drawing. If overflow level control elbows are used near both ends of the water box, the sliding control link 82 may be pivotally connected appropriately to each overflow elbow so that they may be operated simultaneously and equally. However, separate controls may be used for each overflow elbow if desired.

In the above discussion it has been assumed that a proper feed of liquid is supplied to the water box at all times, because liquid is constantly being withdrawn from the box over the tip of the apron cloth and through the overflow elbow. However, although a simple inlet of liquid to the water box near one or both ends between the end seals might furnish a satisfactory overall quantity of liquid, the even distribution of liquid across the entire width of the machine, i.e., the entire length of the water box, is necessary for truly uniform coating or spreading across the width of roll or paper web being processed. For this reason, and according to the present invention an elongated inlet header pipe 90 is provided, extending substantially the entire length of the water box outside of the back wall 16, and it is provided with a plurality of individual branch connector fittings 92, eachleading to and carrying its individual control valve 94. On each connector fitting, above its control valve, an inlet elbow 96 directs incoming liquid to a curved inlet tube 93. Because of brackets, supports and other mechanisms carried by the back wall 16 of the water box, it may not be possible to provide connector fittings 92 on the inlet header pipe 90 at even spacings, but a sufiicient number of fittings is provided so that the open end 99 of a branch inlet tube 98 may be located approximately ten to twelve inches from an adjacent inlet tube open end, uniformly along the length of the water box. In order to position these open tube ends uniformly when the branch fittings and valves feeding them are not spaced uniformly along the header, certain of the tubes 98 may be extended sidewise in one direction or the other after passing through the wall 16 and over the top edge of the dam 32. This is indicated in FIGS. 1 and 2. Moreover, the location and direction of discharge of the open ended inlet tubes is important in obtaining improved effects, especially when the liquids being used are heated liquids or suspensions of chemicals. For this purpose each of the tubes 98 is curved around and downwardly so that its open end 99 discharges into the liquid near the upper face of the apron cloth 30 in a direction away from the spreading tip of the apron cloth, back toward the base of the clamping darn 32 as shown in FIG. 9. This positioning and direction of the branch inlet openings gives extremely good distribution of the liquid and mixing of chemicals, inducing a rotary agitation of the liquid as it flows along the apron cloth and against the dam. This agitation prevents settling of solids from suspensions, disperses the liquid and keeps the temperature uniform in the liquid throughout the length of the water box across the machine. The inlet tubes and the header pipe may be suitably supported from the water box as by clamp blocks 100 secured to each inlet tube and carried by the Walls 16.

Inlet header and drainage conduit connections are of suitable flexible or jointed character as will be readily understood, so that the water box and the apparatus carried thereby may be tilted about its trunnions 20 without interference. Each of the branch inlet tubes may be adjusted in flow individually by its valve 94 to insure maximum uniformity of flow and distribution from the header to the water box. Besides the usual tilting control of the box as a whole, further control of the liquid level in the box and control of the spreading effect from the lip of the apron cloth is obtained by varying the angle of the overflow level control elbow or elbows as above explained. In an emergency, as when it is desired to stop the action of the water box and discontinue spreading or coating of liquid, it may be desirable to lower the liquid 6 level in the box abruptly without changing the tilt of the box. When this becomes necessary, the sliding control link 82 is moved in such a direction and extent as to rotate the overflow elbow 58 until its open end edge 60 in the water box lies adjacent the apron cloth or bottom of the box. When this is done, natural drainage through the discharge conduit 64 takes place immediately and the liquid level drops appropriately. The same arrangement can be used to empty or dump the water box prior to changing an apron cloth or seal mat, or in other circumstances as when the machine is shut down or being prepared for cleaning.

As will be evident from the foregoing description, cer tain aspects of this invent-ion are not limited to the particular details set forth as an example, and it is contemplated that various and other modifications and applications of the invention will occur to those skilled in the art. It is therefore intended that the appended claims shall cover such modifications and applications as do not depart from the true spirit and scope of the invention.

What is claimed as new and is desired to be secured by Letters Patent of the United States is:

1. For use with a rotating roll in a papermaking machine, a liquid spreading chemical and water box of the kind having an L-shaped member forming the box body with a back wall and a bottom wall at right angles to each other,

means supporting said box body across the roll in the machine with the free edge of said bottom wall adjustably positioned adjacent the surface of the roll and an apron cloth carried by said box body with an edge lip extending beyond said free edge of said bottom wall into adjustable liquid spreading contact with said rotating roll across its surface;

that improvement comprising said apron cloth overlying substantially the entire said bottom wall and supported thereon,

a dam wall adjustably slidably carried by said box body back wall in a position parallel to said back wall and above said bottom wall with a bottom edge on said slidable dam wall directed toward said bottom wall and the apron cloth thereon, and

adjustable clamping means exerting pressure on said dam toward said bottom wall to slide said dam and removably seal said bottom edge of said dam against said apron cloth and clamp said apron cloth between said dam and said bottom wall,

release of pressure from said clamping means permitting sliding adjustment on and removal from said bottom wall, of said apron cloth.

2. For use with a rotating roll in a papermaking machine, a liquid spreading chemical and water box of the kind having an L-shaped member forming the box body with a back wall and a bottom wall at right angles to each other,

means supporting said box body across the roll in the machine with the free edge of said bottom wall adjusitiably positioned adjacent the surface of the roll an an apron cloth carried by said box body with an edge lip extending beyond said free edge of said bottom wall into adjustable liquid spreading contact with said rotating roll across its surface;

that improvement comprising said apron cloth overlying substantially the entire said bottom wall and supported thereon,

a dam Wall adjustably slidably carried by said box body back wall in a position parallel to said back wall and above said bottom wall with a bottom edge on said lslidable darn wall directed toward said bottom wall and the apron cloth thereon,

adjustable clamping means exerting pressure on said dam toward said bottom wall to slide said dam and removably seal said bottom edge of said dam against said apron cloth and clamp said apron cloth between said dam and said bottom wall,

release of pressure from said clamping means permitting sliding adjustment on and removal from said bottom wall, of said apron cloth, and

an end seal for each end of said box carried by'said dam above said bottom wall at a selected adjustable position near an end of said box, and

having sealing surfaces engageable against said dam and apron cloth to form a liquid confining end wall in the box.

3. For use with a rotating roll in a papermaking ma chine, a liquid spreading chemical and water box of the kind having an elongated L-shaped member forming the box body with an elongated back wall and an elongated bottom wall at right angles to each other,

means tiltably supporting said box body at its ends across the width of the machine with the free edge of said bottom Wall adjustably positioned adjacent the surface of the rotating roll in the machine, and

an apron cloth carried by said box body with an elongated edge lip extending beyond said free edge of said bottom wall into adjustable liquid spreading contact with said rotating roll surface;

that improvement comprising an elongated flat resilient sealing mat overlying substantially the entire said bottom wall and supporting said apron cloth thereon,

an elongated dam wall adjustably carried by said back Wall, with a clamping edge directed toward said bottom wall and the sealing mat and apron cloth thereon, and

means exerting adjustable pressure on said dam to removably seal said clamping edge against said apron cloth and clamp said apron cloth and mat against said bottom wall,

relief of pressure on said dam permitting sliding adjustment on and removal from said bottom wall, of said apron cloth and sealing mat.

4. For use with a rotating roll in a papermaking machine, a liquid spreading chemical and water box of the kind having an elongated L-shaped member forming the box body with an elongated back wall and an elongated bottom wall at right angles to each other,

means tiltably supporting said box body at its ends across the width of the machine with the free edge of said bottom wall adjustably positioned adjacent the surface of the rotating roll in the machine, and

an apron cloth carried by said box body with an elongated edge lip extending beyond said free edge of said bottom wall into adjustable liquid spreading contact with said rotating roll surface;

that improvement comprising an elongated sealing mat overlying substantially the entire said bottom wall and supporting said apron cloth thereon, an elongated dam wall adjustably carried by said back wall, with a clamping edge directed toward said bottom wall and the sealing mat and apron cloth thereon,

means exerting adjustable pressure on said dam to removably seal said clamping edge against said apron cloth and clamp said apron cloth and mat against said bottom wall;

an end seal for each end of said box having sealing surfaces engageable against said dam and said apron cloth,

end seal clamps carried by said dam movably holding each said end seal on said dam at a selected longitudinally adjustable position near an end of said box 8 body and pressing said sealing surface against said dam and apron cloth to form longitudinally adjustable liquid confining end walls in the box. 5. For use with a rotating roll in a papermaking machine, a liquid spreading chemical and Water box of the kind having an L-shaped member forming the box body With a back wall and a bottom wall at right angles to each other,

means supporting said box body across the roll in the machine with the free edge of said bottom Wall adjustably positioned adjacent the surface of the roll and an apron cloth carried by said box body with an edge lip extending beyond said free edge of said bottom wall into adjustable liquid spreading contact with said rotating roll across its surface;

that improvement comprising a liquid inlet header with multiple branches extending therefrom carried by said box body,

individually controllable liquid inlet ends on the branches substantially uniformly spaced one from another in said box and positioned to direct incoming liquid therefrom above said apron cloth in a direction away from its edge lip and the rotating roll, whereby liquid in said box above said apron cloth is agitated. 6. For use with a rotating roll in a papermaking machine, a liquid spreading chemical and water box of the kind having an L-shaped member forming the box body with a back wall and a bottom wall at right angles to each other,

means supporting said box body across the roll in the machine with the free edge of said bottom wall adjustably positioned adjacent the surface of the roll and an apron cloth carried by said box body with an edge lip extending beyond said free edge of said bottom wall into adjustable liquid spreading contact with said rotating roll across its surface;

that improvement comprising V a liquid inlet header with multiple branches extending therefrom carried by said box body back wall, individually controllable liquid inlet ends on the branches substantially uniformly spaced one from another in said box and positioned to direct incoming liquid therefrom above said apron cloth in a direction away from its edge lip and the rotating roll; an overflow pipe elbow having one leg rotatably mounted through said box body back wall and leading to a liquid outlet,

said overflow elbow having the end of its other leg opening into liquid contained in said box at an overflow level determined by the angular position of rotation of said elbow, and

movable means carried by said back wall controlling the angular position of rotation of said pipe elbow and thus the overflow level of liquid in the box.

7. For use with a rotating roll in a papermaking machine, a liquid spreading chemical and Water box of the kind having an elongated L-shaped member forming the box body with an elongated back wall and an elongated bottom wall at right angles to each other,

means tiltably supporting said box body at its ends across the width of the machine with the free edge of said bottom wall adjustably positioned adjacent the surface of the rotating roll in the machine, and an apron cloth carried by said box body with an elongated edge lip extending beyond said free edge of said bottom Wall into'adjustable liquid spreading contact with said rotating roll surface; that improvement comprising said apron cloth overlying substantially the entire said bottom wall and supported thereon,

an elongated dam adjustably carried by said back wall, with a clamping edge directed toward said bottom wall and the apron cloth thereon,

means exerting adjustable pressure on said dam to removably seal said clamping edge against said apron cloth and clamp said apron cloth against said bottom wall;

a liquid inlet header with multiple branch inlets extending therefrom carried by said back Wall of said box body,

-a control valve in each branch inlet,

curved branch inlet tubes on the branch inlets beyond the control valves thereof, said tubes having open ends substantially uniformly spaced one from another along the length of said box and said open ends being positioned to direct incoming liquid therefrom along said apron cloth in a direction away from said free edge of said bottom wall and toward said dam, whereby liquid contained in said box is agitated.

8. For use with a rotating roll in a papermaking machine, a liquid spreading chemical and water box of the kind having an L-shaped member forming the box body with a back wall and a bottom wall at right angles to each other,

means supporting said box body across the width of the machine with the free edge of said bottom wall adjustably positioned adjacent the surface of the rotating roll in the machine, and

an apron cloth carried by said box body with an edge lip extending beyond said free edge of said bottom wall into adjustable liquid spreading contact with said rotating roll surface;

that improvement comprising said apron cloth overlying substantially the entire said bottom wall and supported thereon,

a darn wall adjustably carried by said back wall, with a clamping edge directed toward said bottom wall and the apron cloth thereon,

means exerting adjustable pressure on said dam to removably seal said clamping edge against said apron cloth and clamp said apron cloth against said bottom wall;

an overflow pipe elbow with one leg rotatably mounted and sealed through said dam and leading to a liquid discharge conduit,

the other leg of said elbow having an end opening into the area between said dam and said apron cloth at an overflow level determined by the angular position of rotation of said elbow, and

means slidably carried by said back wall controlling the angular position of rotation of said pipe elbow in said dam, whereby the overflow level of liquid in said box is determined and liquid above that level is drained through the liquid discharge conduit.

9, For use with a rotating roll in a papermaking machine, a liquid spreading chemical and water box of the kind having an elongated L-shaped member forming the box body with a back wall and a bottom wall at right angles to each other,

means supporting said box body across the width of the machine with the free edge of said bottom wall adjustably positioned adjacent the surface of the rotating roll in the machine, and

an apron cloth carried by said box body with an elongated edge lip extending beyond said free edge of said bottom wall into adjustable liquid spreading contact with said rotating ro-ll surface;

that improvement comprising said apron cloth overlying substantially the entire said bottom wall and supported thereon,

an elongated dam adjustably carried by said back wall, with a clamping edge directed toward said bottom 'wall and the apron cloth thereon,

means exerting adjustable pressure on said dam to removably seal said clamping edge against said apron cloth and clamp said apron cloth against said bottom wall;

a liquid inlet header with multiple branch inlets extending therefrom carried by said back wall of said box body,

a control valve in each branch inlet,

open ends on the branch inlets beyond the control valves thereof, said open ends being substantially uniformly spaced one from another along the length of said box and being positioned to direct incoming liquid therefrom above said apron cloth in a direction away from said free edge of said bottom wall and toward said dam, whereby liquid contained in said box is agitated;

an overflow pipe elbow having one leg rotatably mounted through said dam and leading to a liquid discharge conduit and having the end of the other leg opening into the area between said dam and said apron cloth at an overflow level determined by the angular position of rotation of said elbow, and

means movably carried by said back wall controlling the angular position of rotation of said pipe elbow in said dam, to control the overflow level of liquid in said box.

References Cited by the Examiner UNITED STATES PATENTS 2,301,535 11/1942 Green 101-210 2,439,802 4/1948 Francis 1l8407 2,514,653 7/1950 Lerch 101-364 2,918,899 12/1959 Munton et a1. 118259 2,920,558 1/1960 Hewlett 101-364 DONALL H. SYLVESTER, Primary Examiner.

MORRIS O, WOLK, Examiner. 

1. FOR USE WITH A ROTATING ROLL IN A PAPERMAKING MACHINE, A LIQUID SPREADING CHEMICAL AND WATER BOX OF THE KIND HAVING AN L-SHAPED MEMBER FORMING THE BOX BODY WITH A BACK WALL AND A BOTTOM WALL AT RIGHT ANGLES TO EACH OTHER, MEANS SUPPORTING SAID BOX BODY ACROSS THE ROLL IN THE MACHINE WITH THE FREE EDGE OF SAID BOTTOM WALL ADJUSTABLY POSITIONED ADJACENT THE SURFACE OF THE ROLL AND AN APRON CLOTH CARRIED BY SAID BOX BODY WITH AN EDGE LIP EXTENDING BEYOND SAID FREE EDGE OF SAID BOTTOM WALL INTO ADJUSTABLE LIQUID SPREADING CONTACT WITH SAID ROTATION ROLL ACROSS ITS SURFACE; THAT IMPROVEMENT COMPRISING SAID APRON CLOTH OVERLYING SUBSTANTIALLY THE ENTIRE SAID BOTTOM WALL AND SUPPORTED THEREON, A DAM WALL ADJUSTABLY SLIDABLY CARRIED BY SAID BOX BODY BACK WALL IN A POSITION PARALLEL TO SAID BACK WALL AND ABOVE SAID BOTTOM WALL WITH A BOTTOM EDGE ON SAID SLIDABLE DAM WALL DIRECTED TOWARD SAID BOTTOM WALL AND THE APRON CLOTH THEREON, AND ADJUSTABLE CLAMPING MEANS EXERTING PRESSURE ON SAID DAM TOWARD SAID BOTTOM WALL TO SLIDE SAID DAM AND REMOVABLY SEAL SAID BOTTOM EDGE OF SAID DAM AGAINST SAID APRON CLOTH AND CLAMP SAID APRON CLOTH BETWEEN SAID DAM AND SAID BOTTOM WALL, RELEASE OF PRESSURE FROM SAID CLAMPING MEANS PERMITTING SLIDING ADJUSTMENT ON AND REMOVAL FROM SAID BOTTOM WALL, OF SAID APRON CLOTH. 